We have 2 Polish X hens, and a range of commercial layers. One of the hens in the link above, makes a crow nothing like the others hens. Most of the hens go "bok bok bok bwaaark". But this hen makes this funny noise from about 5am onwards. She is the only hen I can hear from the house. The other polish hen never even makes a sound. Is this a normal chicken sound? She is a bit of a grumpy thing, cute, but just gets mad at the world and is highly suspicious of everything we do. Could it be a warning crow?